Book

Book is a constant object of visual work for the literate population of the country; its qualities, as scientific research and observations show, affect the state of vision of the entire population, especially those groups for whom the book is an object of professional activity. For these latter groups, the format of the B. also acquires special significance, largely determining the working position of the person working with the B. In addition, the B. as an object of mass use must satisfy certain requirements in terms of reducing the possibility of transmitting infection through it. From a hygienic point of view, the following types of printed works deserve the most attention: 1) B. educational, or, as they are often called, working; 2) B. for reading (literary works, artistic publications, children's literature, journals); 3) reference publications (reference books, dictionaries, catalogs); 4) mass brochure (socio-political, popular scientific, etc.). All the listed types and varieties of B. present different requirements for eye work: working books require prolonged strain, reference books require short strain; books for reading and mass brochures require relaxed, freely adjustable visual work. In terms of hygiene and rationalization of labor, the B. must possess properties that provide the best conditions for visual work, under which work is least tiring and most productive, since in the same unit of time one can work through a larger number of pages of a well-printed B. than of a poorly printed one. Visual fatigue weakens the perception of characters, i.e., slows down reading, causes flickering in the eyes, headache, unpleasant physical condition. Examinations of vision in students repeatedly indicated a very significant development of myopia, increasing with age (duration of study). Of course, the development of myopia in students, besides heredity, besides intense reading, was also influenced by other factors of the external environment and work regime, such as poor lighting, etc.; but undoubtedly, under all these circumstances, a poorly published school B. played the main role. Hygienic requirements for educational books were experimentally developed by German scientists Cohn, Weber, and others. Legislatively, the standards were first published in Russia with the closest participation of Khlopin (1905) ("Standards for sanitary control of textbooks and teaching aids"), and more recently in America and in the USSR-by the commission of the Moscow Department of Public Education and the Institute of School Work Methods (1928). Through the experimental work and observations of various authors, it has been established that for easy perception and less fatigue of the visual organ, letter signs must have a certain size. The elements for determining this size are the constituent parts of the letter-its strokes, which must have certain dimensions in length (height), width (thickness), and must be located at a certain distance from each other. The readable page is normally at a distance of about 36 cm from the eyes. Letters are perceived mainly by the outline of the main strokes, first of all the vertical ones. The finer the strokes, the closer they are to each other, the greater the strain required from the eyes when reading (thickening of the lens, bringing the eyes closer to the book, and consequently tilting the head, etc.). Most researchers (and published standards) accept the following sizes of the font of the working B. for the 2nd and subsequent years of study: height of main strokes-1.5-1.75-2.0 mm, thickness-0.25 mm, distance between them-0.5 mm; thickness of connecting (auxiliary) strokes-0.1 mm. Fonts "Latin" and "ordinary-garniture 6" (according to the all-union standard-fonts No. 8 I and No. 2) of size from 10 to 16 typographic points (large body, cicero and tercia) satisfy these standards. For B. for special purposes, the standards are changed: for example, for primers and books for initial reading they are increased (height of font-up to 3-4 mm, i.e. in typographic measures-size 16-28, according to the font standard-No. 3, "educational"); for reference B.-they are decreased (height can be less than 1.5 mm, but more than 1 mm). Besides size, the main hygienic requirement for the font is its clarity, legibility for the eye, i.e. simplicity of design. The font should be simple, without affectation, additional strokes and "decorative" elements, because each extra line makes visual work difficult. From this point of view, fonts of "ordinary" and "Latin" design (stand. Nos. 2, 3 and 8) are most satisfactory. For the same reasons, the use of italics is not recommended in textbooks for the first years of study (which should be replaced by setting in spacing). A normal letter, however, does not determine the conditions of visual work as a whole; the latter are given by the hygienic composition of the entire page. A long line requires constant movement of the head and eyeball and excessive strain of attention when moving from one line to another; crowding of letters also makes reading difficult. Therefore, the following hygienic requirements are made for the setting of the B. The length of the line is determined from 81.2-100 mm (4¹/₂-5¹/₂ typographic squares) for younger ages and up to 108 mm and more (6-6¹/₂ squares) for older; the distance between lines (interlinear spacing)-3 mm (which means the need to use when setting body 3-point spacers, and when "cicero"-2-point); the minimum distance between individual words (ap-prosh)-not less than 2 mm (5-6 typographic points); finally, the distance between individual letters-not less than 0.5 mm. In sum, these requirements determine the density of the font (i.e. the number of letters per 1 cm²), which should not exceed 14 letters. To this must be added that the "margins" of the book play a large hygienic role: narrow margins contribute to fatigue, wider ones facilitate reading. The indicated standards for line length also determine the most desirable format of the book from a hygienic point of view, which was taken into account when introducing all-union standards for paper formats. In the system of these standards, formats A₅ (148 x 210 mm) and B_v (125 x 176 mm) are provided for the educational book, in which the desired line length is observed. The format of the book often, besides vision, also affects the position (posture) of the person working on the B., especially when the reader must make excerpts from it: a large format usually forces him to take an uncomfortable posture (lean against the table with his chest, etc.). Hence also follows the need for possible limitation of the formats of working books. Under all these conditions, it is also necessary to observe the clarity of the printing itself, the intensity and evenness of the color of all letters and strokes; letters should not blur and be variegated, the intensity of the color of letters on each page and the average on different pages of a given book should be the same. The use of colored printing inks, especially reddish ones, for printing text is unacceptable. No less important than the font is the quality of the paper on which the B. is printed, because even when all the above conditions are observed, the B. may prove unsatisfactory if the paper is unsatisfactory; the latter should have a smooth, smooth, non-glossy, clean surface of white or slightly yellowish color and should not be transparent (for more details-see Paper). The methodology of hygienic control over the B. is not complicated: the strokes of letters are measured with a magnifying glass with a millimeter ruler (with divisions of 0.5 or 0.25 mm, and preferably 0.1 mm), and the density of the font-by counting letters in a square hole cut out of a piece of thin cardboard (1 cm²); the length of the line is measured with a millimeter ruler. To measure the elements of a letter of a given font, it is preferable to take the letter "n". Russian educational and working B., starting from the nineties of the 19th century and up to the present time, have been subjected to numerous and detailed research from a hygienic point of view (in total, more than 1,000 B. have been studied). These studies showed that most publications are unsatisfactory in one respect or another. Thus, Nikitin's study of 348 books (1907) showed the following percentages of unsatisfactory B.: in terms of paper quality-about 80%, in terms of line length-57%, in terms of interlinear spacing-76.5%, in terms of ap-prosh-5%, in terms of font density-15.4%; height of font-rarely below standard; distance between main strokes-below standard in 5%, unsatisfactory thickness of strokes was noted in 14% of books. Consequently, the main defects were on the part of paper and setting. The results of the study of the latest edition of B. are as follows: Kalashnikov, who studied 230 B. in 1928, Kizevetter, who studied 125 B. (I and II levels) in 1929, noted the following shortcomings: poor paper quality-100% and 89%; unsatisfactory interlinear spacing-79% and 70%; excessive line length-63% and 68%; unsatisfactory height of font-21% and 24% (for older age) and 75% (for younger age); insufficient thickness of main strokes-13% and 23.5%; unsatisfactory distance between letters-2%; font density-8%; paleness of printing-45%. Consequently, the most recent studies also confirm the need for hygienic control over the publication of educational, or working B.

Strict adherence to the hygienic requirements for Books, especially educational ones, usually encounters a number of economic difficulties, since the use of larger fonts, larger margins, and a smaller format, while increasing the volume of the book, raises its production cost and selling price. Therefore, the mandatory standards established provide for certain deviations from hygienic requirements, which was reflected in particular in the 'Regulations on the External Design of Educational Books', approved by the State Scientific Council in 1928. There are observations that books that have been used by infectious patients may pose a danger in terms of transmitting infections.

A-vertical cross-section of a letter; B-perspective view of it: Different relationship between the thickness of main and auxiliary strokes: 1-in the 'ordinary' font 2-in the 'English' bold 3-in the 'Latin' light 4-in the 'Corinthian' font The influence of supporting strokes on the clarity of the font: 1-in the 'ordinary' 2-in the 'Latin' 1-leg of the letter; 2-shoulders; 3-eye of the letter (character); 4-signature (crease). Nonpareil |6p. Petit 8 p. Corpus 10 p. Cicero 12 p. Terzia 16 p. Text 20 p. The most commonly used sizes of book fonts; the numbers indicate the size of the pica in typographical points. Latin light; bold Latin light italic; bold Ordinary font Ordinary italic Aldine (semi-English) Academic light; bold Elizabethan upright; italic. Palmyra upright; italic Ancient upright; italic Names of the most commonly used book (text) fonts (samples are given in corpus, i.e., 10 points). 1 l¹ 1 . square 1 1 1 1 1 1 ! : 1 1 1 1 1 1 1 ! 1 » ~T 1 1 1!1!|Ш||1!11|П ? ем | 1 3 1 5 1 6 ) 10 i 1 typographical square=48 typographical points, or 4 ciceros, or 8 nonpareils; 1 typographical point=0.375 mm; 1 square=about 18 mm. For comparison, a centimeter ruler is shown at the bottom.

Grunya got down from the bench, took a rag and wiped the table. She took spoons from the shelf, a large bowl, a salt shaker with salt, put a loaf of bread, a knife, and spread a clean white towel around the table. Sample setting of a textbook for the 2nd year of study. Line length 100 mm (b¹/,. squares); height of main strokes-2.7 mm; thickness of main strokes-0.5 mm; auxiliary-0.2 mm; interlinear spacing (distance between lines)-3.2 mm. Set in 16-point (terzia), Latin font without leading. (To the article Book.) I- infections. Experimental research has also shown that under favorable conditions, some pathogenic bacteria can remain on paper for a considerable time. Therefore, in such cases, disinfection of Books should be carried out, and most importantly, hygienic rules should be observed both in storing Books and in using them (not to moisten fingers with saliva when turning pages, etc.).